Influence of Nonlinear Friction and Disturbance in the Control of a Mechatronic System: CNC Machine Tool Application
The CNC (Computer Numerical Control) machine tools are complex mechatronic systems applied to the manufacture with high precision and high speeds. To achieve high accuracy and operational efficiency, the disturbance and friction, which occur during machining process, should be reduced as low as possible. This paper develops an analysis of influence by cutting force and friction effect in the control of machine tool based on the CNC dynamic model and parameters identification. For this purpose, the study focuses on Coulomb and Viscous nonlinear friction and the external disturbances. The analysis uses control position error, contour error, and stability to determine the influence of friction and disturbance. The results show that Viscous friction has more critical influence on system than the Cutting force and Coulomb. The work contributes in recognizing which parameters have greater influence on the machine behavior through dynamic analysis with the identification strategy, in order to design and improve the control structure for a real CNC system.